Banana Pi BPI-R3 Mini, 5G module, heatsink and fan

Banana Pi Router design BPI-R3/R3 Mini(MT7986)
1

Hi guys,

i need some suggestions… I’m currently creating my own 5G router using the R3-Mini with a Quectel RM502Q-GL. This module inside the board is very “hot”, normally sitting at 65°C (registered to 5G but in idle), and can hit 85°C while in use.

So I want to put a little heatsink on top of it, but the problem can be the FAN. How many mm space are avaliable between latest M.2 slot and the FAN? The most thin heatsink i’ve found is 5mm

Any suggestion on how to configure FAN PWN? I’ve tried this configuration but the fan start and stop all the time, not so much useful

echo 35000 > /sys/class/thermal/thermal_zone0/trip_point_4_temp
echo 45000 > /sys/class/thermal/thermal_zone0/trip_point_3_temp
echo 55000 > /sys/class/thermal/thermal_zone0/trip_point_2_temp

Thanks in advance!

2

I noticed that r3mini inside the vendor case is really hot when touching the case…i have “only” 45-50°C but case is nearly same temperature…too much imho.

So i used these settings

root@bpi-r3-mini:~# echo 45000 > /sys/class/thermal/thermal_zone0/trip_point_3_temp
root@bpi-r3-mini:~# echo 55000 > /sys/class/thermal/thermal_zone0/trip_point_2_temp

With similar result…case is touchable,but fan goes on and off in ~ 5sec steps…maybe we can do something with the other config points in sysfs.

3

currently i’m using this one to keep FAN always-on at medium level

echo 35000 > /sys/class/thermal/thermal_zone0/trip_point_3_temp

5G module can go up to 75°C, while the other part of the unit is touchable… anyway there is no space for 5mm heatsink on the 5G module, so I think fan should be on to avoid overheat :frowning: